Green walls create new urban jungles

By Matthew Knight, CNN

Updated 0238 GMT (1038 HKT) January 31, 2012

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UK company Biotecture have created a green wall for the side of Edgware Road Underground station in London which sits near the busy, and very polluted, Marylebone Road. It is hoped that the new wall will help eradicate some of the air pollution in the area.

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Buildings with green walls are popping up all over the UK thanks to companies like Biotecture. This one is on a library in the town of Grimsby in northeast England.

He also oversaw the creation of a vetical garden on the side of the CaxiaForum, Madrid in 2007.

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The WestBlaak Building (bottom left) in Rotterdam was recently fitted with a green facade which its developers, Rotterdam Climate Intiative, hope will cover large sections of the car park. It has also been created to aid water management and reduce CO2.

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Story highlights

Green walls turn dreary urban facades into vertical banks of color

As well as aesthetic qualities, vertical gardens may also improve air quality

New wall near congested Marylebone Road in London may reduce pollution

Vertical gardens are cropping up all over cities these days, transforming drab urban facades into vibrant jungles of color.

These lush expanses have found their way onto the walls -- both inside and out -- on numerous sites in recent years revitalizing public buildings, hotels, offices and even a multi-storey car park in Netherlands.

Aside from their pleasing aesthetic qualities, vertical gardens could also deliver more practical benefits says Mark Laurence, creative director at Biotecture, a UK company who design and build green walls.

"The market is rapidly moving into looking at how they can provide eco-system services and green infrastructures for urban environments," Laurence said.

Their modular hydroponic system -- where plants sit in a soil-free set up with nutrients delivered through irrigation channels -- can be retrofitted to just about any wall.

A recent creation erected on the side of Edgware Road Underground station in central London is hoping to improve air quality.

"They have taken initial samples and going at regular intervals to take leaf samples. Then they wash these leaf samples to see how much particulate matter has adhered to the leaves," said Laurence.

The leaves also have an electrostatic charge that also attracts particles.

"A researcher I was speaking to recently reckons green walls in urban canyon environments (areas where walls are higher than the width of the road separating them) are more effective than trees at collecting particles because the way the wind eddies around and then moves down the wall," Laurence said.

Some believe that in less polluted areas, green walls could be employed to grow food, which could aid urban food security. Biotecture have successfully trialled a wall which grew 45 varieties of vegetable.

Furthermore, there's nothing stopping people building their own, more basic green walls at home, Laurence says.

There are various systems for DIY constructions with most requiring a compost-based system, he says, but homemade hydroponic systems can be made using plastic bottles. All you need is irrigation and adequate light.